//
//  STabBar.swift
//  SWeiboBoom
//
//  Created by Angus.丶 ShangYang on 16/8/9.
//  Copyright © 2016年 Angus_Shyang. All rights reserved.
//


import UIKit
//声明一个协议,继承自NSObjectProtocol
protocol STabBarDelegate:NSObjectProtocol{
    //声明方法
    func tabBarButtonClick()
    
}

class STabBar: UITabBar {

    //声明一个代理
    weak var sDelegate:STabBarDelegate?
    
    override init(frame: CGRect) {
        super.init(frame: frame)
        setupUI()
    }
    
    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:)has not been implemented")
    }
    
    //MARK:- 监听方法
    func buttonClick(){
        sDelegate?.tabBarButtonClick()
    }
    
    //MARK:- 设置视图
    private func setupUI(){
        addSubview(composeButton)
    }
    
    
    //给子控制器设置frame
    override func layoutSubviews() {
        super.layoutSubviews()
        //子控件的宽度
        let childW = self.frame.width * 0.2
        var index:CGFloat = 0
        //遍历子控件
        for value in self.subviews {
            //NSClassFromString 通过字符串转class
            if value.isKindOfClass(NSClassFromString("UITabBarButton")!){
                //设置frame
                value.frame.size.width = childW
                value.frame.origin.x = index * childW
                
                index++
                
                //为了给撰写按钮留位置
                if index == 2{
                    index++
                }
            }
        }
        //设置撰写按钮的frame
        composeButton.center.x = self.frame.width * 0.5
        composeButton.center.y = self.frame.height * 0.5
    }
    
    //MARK: - 懒加载控件
    //撰写按钮
    private lazy var composeButton:UIButton = {
        let button = UIButton()
       //点击事件
        button.addTarget(self, action: "buttonClick", forControlEvents: UIControlEvents.TouchUpInside)
        //设置背景图片
        button.setBackgroundImage(UIImage(named:"tabbar_compose_button_highlighted"), forState: UIControlState.Highlighted)
        button.setBackgroundImage(UIImage(named:"tabbar_compose_button"), forState: UIControlState.Normal)
        //设置图片
        button.setImage(UIImage(named:"tabbar_compose_icon_add_highlighted"), forState: UIControlState.Highlighted)
        button.setImage(UIImage(named:"tabbar_compose_icon_add"), forState: UIControlState.Normal)
        //自适应
        button.sizeToFit()
        
        return button
    }()
    
}














